class Animal:
    def __init__(self, species, sound):
        if species in ['猫','狗','羊','猴子','老虎','大象']:
            self.species =species
            self.sound =sound
        else:
            self.species = None
            self.sound = None
    def speak(self):
        if self.species == None:
            print('动物园里没有动物，游戏结束！！');
            return False
        else:
            print(self.species, self.sound)
            return  True
print('动物园里有什么？')
flag = True
while flag:
    s = input('请输入动物种类叫声       ：')
    list1= s.split(' ')
    animal = Animal(list1[0],list1[1])
    slag = animal.speak()

